The present invention relates to a method and apparatus for compressing low pressure steam into steam of higher pressure and temperature without the need for an external energy source. More particularly, the invention relates to a method and apparatus for compressing a portion of low pressure steam, e.g., steam generated by the refining of cellulose-containing materials, into steam of higher pressure and temperature employing the heat energy of the remainder of the low pressure steam.
Various industrial processes produce as a by-product large amounts of heat energy in the form of steam having low pressure and low temperature. Although this low pressure steam has a high heat energy content, many industrial applications for such steam require a higher pressure and temperature. Using an external energy source to compress the low pressure steam is sometimes impractical and costly. Thus, this low pressure steam, even with its high heat content, has a limited field of application. In fact, many times the low pressure steam is just discarded.